Jumping Oak Gall Wasps - Neuroterus saltatorius
"Jumping galls are attached to the leaves of several native oaks in California's Sacramento Valley, including the valley oak (Quercus lobata), blue oak (Q. douglasii ) and Oregon oak (Q. garryana). During favorable years, the undersides (and uppersides) of each leaf contains dozens of galls. When multiplied by the hundreds of thousands of leaves per tree, this accounts for the millions of galls that fall to the ground beneath these oaks, like a shower of tiny BB-shaped bird seed. In fact, some valley residents become dismayed when the galls cover their patios, sidewalks and driveways. Each gall is inhabited by a tiny cynipid gall wasp appropriately named the "jumping oak gall wasp" (Neuroterus saltatorius), formerly named Cynips saltatorius. Since the gall consists of a single cavity or chamber occupied by a single wasp it is termed monothalamous by cecidologists (people who study galls). Since the galls break away from the leaves, they are called "detachable galls." When the minute galls fall to the ground they begin hopping about like fleas. Like jumping beans, the larva inside is active during the summer months, but ceases its activity by late summer and fall when it changes into a pupa. And like jumping beans under jumping bean shrubs, the sound of thousands of jumping galls in the leaf litter beneath oaks resembles the patter of rain drops falling on dry leaves."
